Hydraulic honing machine



June W57 J- E. WRIGHT HYDRAULIC HONING MACHINE 2 Sheets-Sheet 2 Filed Aug. 5 19 4 X l m 3,324,602 HYDRAULIC HUNING MACHINE John E. Wright, Liberty, Ind, assignor to National Automatic Tool Company, Richmond, Va, a corporation of Indiana Filed Aug. 3, 1964, Ser. No. 387,025 17 Claims. (Cl. ll165) This invention relates to a honing machine wherein compact hydraulic means is provided for expanding the honing elements of the honing tool, the use of hydraulic means for this purpose making it possible to have honing tools close together for honing adjacent cylinder bores of an engine block or the like.

One object of the invention is to provide a feed cylinder having a feed piston therein for actuating the push rod of a honing tool, which push rod actuates a wedge in the honing tool to determine the diameter of the honing elements depending upon the axial position of the wedge, an increment feed pump being connected to the cylinder for periodically supplying minute charges of fluid thereto for moving the push rod in the hone element expanding direction.

Another object is to provide the feed cylinder and piston of relatively large area and the increment feed pump with a plunger having a small area to render the increments of feed to the push rod by the feed piston very small relative to the stroke of the increment feed plunger.

Still another object is to provide the feed cylinder and piston also operable to effect initial rapid expansion of the honing elements to the bore of the workpiece in addition to serving as an increment feed means.

A further object is to provide hydraulically operated means for moving the feed cylinder and the increment feed pump as a unit for thereby moving the push rod in the honing element expanding direction for supplying a required working pressure for the honing elements relative to the bore of the workpiece, such means comprising a tool pressure cylinder and piston to which hydraulic pressure is supplied through a pressure reducing valve so that the degree of honing tool pressure may be regulated.

Still a further object is to provide the rapid initial expansion means and the tool pressure hydraulic means under control of a timer to limit the operation thereof, following which the honing tool is automatically reciprocated and simultaneously therewith the feed pump plunger is reciprocated.

An additional object is to provide hydraulic feed means which affords variable hone element pressure and compensation for hone wear as well as micrometrically adjustable, cyclically operable increment feed.

With these and other objects in View, my invention consists in the construction, arrangement and combination of the various parts of my hydraulic honing machine, whereby the objects above contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in detail on the accompanying drawings, wherein:

FIG. 1 is a front elevation of a hydraulic honing machine embodying my invention;

FIG. 2 is an enlarged vertical sectional view on the line 22 thereof, and

FIG. 3 is an operational diagram of the machine.

On the accompanying drawing I have used the reference numeral to indicate a base of the honing machine and 12 a work supporting table thereof. An upright column 14 supports a pair of guide rods 16 on which bearings 18 are vertically slidable. The bearings support a box-like head 20 in which is mounted the mechanism of the honing machine.

The head 20 is adapted to be vertically reciprocated by means of a head reciprocating cylinder HRC in which 3,324,6 2 Patented June 13, 1967 is mounted a head reciprocating piston 22 (shown in FIG. 3) from which a piston rod 24 extends and which is connected to the head 20 as by a nut 26 shown in FIG. 2.

Within the head 20 a spindle 28 is journaled in suitable roller bearings and has means on its lower end for connection with a honing tool 30' shown diagrammatically in FIG. 3. Change speed gears 32 and 34 connect a drive shaft 36 to the spindle 28 for rotating it when the drive shaft is rotated. The upper end of the drive shaft has a splined fitting 38 with which a splined shaft 40 is associated, the shaft being rotated by an electric or hydraulic motor or the like shown at 41 in FIG. 1. The change speed gear 34 is adapted to be shifted with respect to the gear 32 by a shift fork 42, shift rod 44 and shift pinion 46 in the usual manner.

Honing tools of the kind shown at 30 are provided with honing elements 48 capable of expansion in diameter by the operation of a wedge 50 as shown in FIG. 3, and the wedge is actuated by a push rod 52 slidable axially within the spindle 28. A feed cylinder FC and a feed piston 54 therein are provided for axially moving the push rod 52, a piston rod 56 serving as a connection between the feed piston and the push rod through a thrust bearing connection 58 whereby the push rod is free to rotate with the honing tool 30 and the piston rod 56 is held against rotation as by an arm 60.

The feed cylinder PC is supported by a piston rod 62 terminating at its upper end in a piston 64 as shown in FIG. 3 within a tool pressure cylinder TPC. In FIG. 2 a connection 66 between the feed cylinder FC and the piston rod 62 is shown in the form of dished washers which prevent any binding due to misalignment, and a fork arm 68 is provided to prevent rotation of the feed cylinder as it is moved upwardly and downwardly by the piston rod 62.

An increment feed pump IFP is supported by the feed cylinder FC and movable therewith, and has therein a piston 70 from which a pump plunger 72 extends into a pump cylinder 74. The usual pump check valves 76 and 78 are provided for hydraulic fluid from a tank 80 shown in FIG. 3 through a flexible connection 82 and through the check valves to the feed cylinder FC. These check valves, however, must be of precision type with minimum leakage because of small fluid volumes involved as will hereinafter appear.

The increment feed piston 70 is adapted to be hydraulically reciprocated Within a cylinder 69 by alternate introduction of fluid pressure to down and up ports D and U respectively, which are shown in FIGS. 2 and 3. The head reciprocating cylinder HRC, the feed cylinder FC and the tool pressure cylinder TPC are likewise provided with down and up ports as shown in FIG. 3.

This figure also shows a gauge ring 84 above the honing tool 34 adapted to enter the bore 86 of a workpiece 88 when the bore has been honed to the proper diameter as disclosed in Calvert Patents Nos. 2,741,071, 2,790,277 and 2,845,752. A limit switch LS1 is illustrated to be operated by a vane 90 on the head 20, and a limit switch LS2 is adapted to be actuated by dogs 92 and 94 of the head. A limit switch LS3 is adapted to be actuated by an arm 96 on the gauge ring 84.

Practical operation Referring to FIG. 3, a start button ST is shown which, upon being depressed, operates the usual solenoid valves and pneumatic and/or hydraulic controls which result in hydraulic pressure being applied in accordance with operation (1) to the down port D of the head reciprocating cylinder HRC for lowering the head 20 from its elevated position with the honing tool 30 above the workpiece 88 so that the honing tool is entered into the bore 86. Thereupon limit switch LS1 effects operations (2) and (2A) through a timer T which times out in a predetermined period of time to limit the operations (2) and (2A). Operation (2) sends hydraulic pressure to the down port D of the feed cylinder PC for initial rapid expansion of the honing elements 48' while operation (2A)sends hydraulic pressure through a pressure reducing valve PRV to the down port D of the tool pressure cylinder TPC. Thus-the honing elements are rapidly expanded and their pressure against the bore 86 regulated by the pressure reducing valve within the time period allowed by the timer T. I

The downward movement of the head 20 results in the dog-92 operating the limit switch LS2 for elfecting operations (3), (3A), (4) and (4A) shown diagrammatically in FIG. 3. Operation (3) sends hydraulic fluid to the up port U of the head reciprocating cylinder HRC for reversing the motion of the head and as soon as it reaches the top of its stroke again the dog 94 operates the limit switch LS2 for sending hydraulic fluid to the down port of the head reciprocating cylinder and thus the head is reciprocated.

Similarly the limit switch LS2 alternately sends hydraulic fluid in accordance with operations (3A) and (4A) to opposite ends of the increment feed pump cylinder 69 so that each reciprocation of the honing tool a minute charge of hydraulic fluid is pumped by the increment feed pump into the top of the feed cylinder FC. By making the area of the feed pump plunger 72 about for instance, and the area of the piston 3", at Ma" stroke of the plunger results in a stroke of about .002 of the piston 54. This, in, turn, is only about .0002 expansion of the honing elements 48 when the wedge 50 has a 1: 10 slope. Increments this small are particularly needed for diamond hones now being used in the honing field.

The stroke of the plunger 72 is regulated by a stem 98 having threaded thereon an adjusting nut 100. When the increment teed piston 70 is down as shown in FIG. 2 it engages a stop washer 102 whereas when it is up the adjusting nut 100 engages a packing gland 104. The nut 100 may he graduated in a manner similar to a micrometer and thus the degree of increment feed regulated within very close limits.

When the gauge ring 84 enters the bore 86 of the workpiece 88 the operation of the honing machine is stopped by engagement of the arm 96 with the limit switch LS3 which effects operations (5) to send hydraulic fluid to the up port U of the tool pressure cylinder TPC, and operation (5A) to send hydraulic pressure to the up port U of the feed cylinder PC, thereby contracting the honing elements 48. Also operation (5B) occurs sending hydraulic pressure to the up port of the head reciprocating cylinder so that the head stops in the raised position shown in FIG. 3 for substitution of another workpiece 88, and for the beginning of the honing cycle on it by again depressing the start button ST.

The electric circuit, relays and control valves for the various operations described are, of course, designed to exhaust from the down port of each cylinder when the up port receives oil and vice versa. Electric and hydraulic circuitry of this kindv is standard equipment in the machine tool art and need not be gone into in detail.

From the foregoing specification it will be obvious that I have provided a readily adjustable means for hydraulic increment feed applied to the push rod 52 of the honing tool 30. The design of the parts and the operation is such that there are periodic feed increments corresponding'to the reciprocations of the honing tool. The feed cylinder, in addition to being actuated by the increment fefed pump, is also actuated for rapid advance and for tool pressure'determination, the latter operation being accomplished by suspending the entire feed cylinder and increment feed pump from the piston 64 in the tool pressure cylinder TPC.

- Some changes may be made 'in the construction and arrangement of the parts of my hydraulic honing machine without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims any modified forms of structure or use of mechanical equivalents which may reasonably be included within their scope.

I claim as my invention:

1. In a hydraulic honing machine, a honing spindle adapted to support a honing tool having honing elements and means to expand the same with respect to the bore of a workpiece, means for rotating said spindle, a push rod adapted to operate said honing element expanding means,-and hydraulic means for controlling the reciprocations of said push rod comprising a feed cylinder, a feed piston therein connected with said push rod, an increment feed pump connected with said feed cylinder to periodically supply minute charges of fluid thereto, means for reciprocating said honing tool with respect to the workpiece, and means for effecting operation of said increment feed pump to periodically supply said minute charges of fluid to said feed cylinder.

2. A honing machine in accordance with claim 1 wherein said increment feed pump comprises a cylinder and a piston of small area and said feed cylinder and feed piston are of larger area to render the increments of feed to said push rod by said feed piston very small in relation to the stroke of said increment feed pump.

3. A honing machine in accordance with claim 2 wherein said increment feed pump piston is reciprocated in synchronism with the reciprocations of said honing tool.

4. A honing machine in accordance with claim 1 wherein means is provided to additionally supply fiuid to said feed cylinder for rapid initial movement of said push rod in the hone element expanding direction.

5. A honing machine in accordance with claim 1 where in hydraulic means is provided for moving said feed cylinder and said increment feed pump as a unit for thereby moving said push rod in the hone element expanding direaction for supplying a required working pressure for the honing elements relative tothe bore of the workpiece.

6. A honing machine in accordance with claim 4 wherein hydraulic means is provided for moving said feed cylinder and said increment feed pump as a unit for thereby moving said push rod in the hone element expanding direction for supplying a required working pressure for the honing elements relative to the bore of the workpiece.

7. A honing machine in accordance with claim 6 wherein means is provided for additionally operating said last hydraulic means for moving said feed cylinder and said increment feed pump as a unit for thereby moving said push rod in the hone element contracting direction for initial retraction.

8. A honing machine in accordance with claim 7 wherein said last means is responsive to entry of a bore gauge into the bore of the workpiece.

9. A honing machine in accordance with claim 4 wherein means is responsive to entry of a bore gauge into the bore of the workpiece for additionally supplying fluid to said feed cylinder for rapid movement of said push rod in the bone element contracting direction.

10. A honing machine in accordance with claim 5 wherein a pressure reducing valve is associated with said last hydraulic means to determine the hone element pressure.

11. A honing machine in accordance with claim 1 wherein said means for reciprocating said honing tool comprises a head supporting said feed cylinder and said increment feed pump, a head reciprocating cylinder and piston operatively connected with said head, and dogactuated means for reversing the flow of fluid to said head reciprocating cylinder in response to reciprocations of said head.

12. A honing machine in accordance with claim 11 wherein said dog-actuated means also effects operation of said increment feed pump.

13. A honing machine in accordance with claim 11 wherein said increment feed pump comprises a piston and said dog-actuated means also effects reciprocations of said piston of said increment feed pump.

14. A honing machine in accordance with claim 4 wherein control means is provided to efle-ct operation of said means to supply additional fluid to said feed cylinder responsive to movement of the honing tool in the workpiece.

15. A honing machine in accordance with claim 14 wherein a timer is provided to limit the rapid initial expansion movement of said push rod.

16. A honing machine in accordance with claim 5 wherein a timer is provided to limit operation of said last hydraulic means.

17. A honin machine in accordance with claim 16 wherein a pressure reducing valve is associated with said last hydraulic means to determine the hone element pressure.

References Cited UNITED STATES PATENTS 15 LESTER M. SWINGLE, Primary Examiner. 

1. IN A HYDRAULIC HONING MACHINE, A HONING SPINDLE ADAPTED TO SUPPORT A HONING TOOL HAVING HONING ELEMENTS AND MEANS TO EXPAND THE SAME WITH RESPECT TO THE BORE OF A WORKPIECE, MEANS FOR ROTATING SAID SPINDLE, A PUSH ROD ADAPTED TO OPERATE SAID HONING ELEMENT EXPANDING MEANS, AND HYDRAULIC MEANS FOR CONTROLLING THE RECIPROCATIONS OF SAID PUSH ROD COMPRISING A FEED CYLINDER, A FEED PISTON THEREIN CONNECTED WITH SAID PUSH ROD, AN INCREMENT FEED PUMP CONNECTED WITH SAID FEED CYLINDER TO PERIODICALLY SUPPLY MINUTE CHARGES OF FLUID THERETO, MEANS FOR RECIPROCATING SAID HONING TOOL WITH RESPECT TO THE WORKPIECE, AND MEANS FOR EFFECTING OPERATION OF SAID INCREMENT FEED PIMP TO PERIODICALLY SUPPLY SAID MINUTE CHARGES OF FLUID TO SAID FEED CYLINDER. 